最近接到需求，项目的图片要随着主题色的改变，做相应的改变，在这里取两种类型的图片来做说明
第一种图片是：背景色跟随主题，图片内容为白色，思路是先画个纯色主题色背景图片，然后把白色的图片和你所画的背景图片做拼接，实现如下：
Snip20160113_3.png
UIImage+Extension.h文件
#import <UIKit/UIKit.h>
@interface UIImage (Extension)
/** 染背景色*/
- (UIImage *)image:(UIImage *)image withColor:(UIColor *)color;
/** 染内容*/
- (UIImage *)imageContentWithColor:(UIColor *)color ;
/** 拼接图片*/
- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2；
UIImage+Extension.m文件
// 画背景
- (UIImage *)image:(UIImage *)image withColor:(UIColor *)color
{
CGRect rect = CGRectMake(0.0f, 0.0f, image.size.width, image.size.height);
UIGraphicsBeginImageContextWithOptions(rect.size, NO, image.scale);
CGContextRef context = UIGraphicsGetCurrentContext();
[image drawInRect:rect];
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextSetBlendMode(context, kCGBlendModeNormal);
CGContextFillRect(context, rect);
UIImage*newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
// 合成图片
- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2 {
UIGraphicsBeginImageContext(image1.size);
// Draw image2 哪个图片在最下面先画谁，在这里有先后顺序
[image2 drawInRect:CGRectMake(0, 0, image2.size.width, image2.size.height)];
// Draw image1
[image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return resultingImage;
}
// 画带有边框的圆，在画这个图片的时候用到了，也写出来吧，但是边框设的为零，
- (UIImage *)circleImageName:(NSString *)path borderWith:(double)border colorWith:(UIColor *)color
{
UIImage *img=[UIImage imageNamed:path];
UIGraphicsBeginImageContext(img.size );
CGContextRef ctr =UIGraphicsGetCurrentContext();
double radius=img.size.height>img.size.width?(img.size.width/2):(img.size.height/2);
radius/=2;
double centerx=img.size.width/2;
double centery=img.size.height/2;
[color set];
// CGContextSetLineWidth(ctr, border);
CGContextAddArc(ctr, centerx, centery, radius+border,0, M_PI_2*4,YES);
CGContextFillPath(ctr);
CGContextAddArc(ctr, centerx, centery, radius,0, M_PI_2*4,YES);
CGContextClip(ctr);
[img drawInRect:CGRectMake(0,0, img.size.width, img.size.height)];
UIImage *newImg=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImg;
}
第二种图片就是：图片内容随着主题色改变其他背景透明
Snip20160113_2.png
UIImage+Extension.m文件
- (UIImage *)imageContentWithColor:(UIColor *)color {
if (!color) {
return nil;
}
UIImage *newImage = nil;
CGRect imageRect = (CGRect){CGPointZero,self.size};
UIGraphicsBeginImageContextWithOptions(imageRect.size, NO, self.scale);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextScaleCTM(context, 1.0, -1.0);
CGContextTranslateCTM(context, 0.0, -(imageRect.size.height));
CGContextClipToMask(context, imageRect, self.CGImage);//选中选区 获取不透明区域路径
CGContextSetFillColorWithColor(context, color.CGColor);//设置颜色
CGContextFillRect(context, imageRect);//绘制
newImage = UIGraphicsGetImageFromCurrentImageContext();//提取图片
UIGraphicsEndImageContext();
return newImage;
}
第二种图片借鉴网友提供的思路，特此感谢！
